1. Field of the Invention
The present invention relates to a carrier cleaning apparatus which cleans carrier vapor when it is generated from a wet type electrophotographic image forming apparatus, and a wet type electrophotographic image forming apparatus having the same.
2. Description of the Related Art
Generally, a wet type electrophotographic image forming apparatus irradiates a laser beam onto an image bearing body such as a photosensitive drum to form an electrostatic latent image thereon. A developer liquid is attached to the electrostatic latent image and therefore visualizes the latent image. The visualized image is transferred onto a predetermined paper sheet, representing an intended image form. The wet type electrophotographic image forming apparatus has a relatively clearer image than a dry type which uses toner powder, and therefore, is more suitable for the printing of color images.
FIG. 1 is a schematic view of a conventional wet type electrophotographic image forming apparatus.
As shown in FIG. 1, a conventional wet type electrophotographic image forming apparatus 10 comprises an image forming apparatus body 11, a plurality of photosensitive drums 12, 13, 14, 15 on which electrostatic latent images are formed, a plurality of electrifying devices 22, 23, 24, 25 which charge the respective photosensitive drums 12, 13, 14, 15 to a predetermined voltage, a plurality of light exposure devices 32, 33, 34, 35 which irradiate laser beams onto the electrified photosensitive drums 12, 13, 14, 15, respectively, a plurality of developing units 52, 53, 54, 55 which visualize the images onto the photosensitive drums 12, 13, 14, 15 by supplying developer liquid, a plurality of first transfer rollers 62, 63, 64, 65 which transfer visible images of the photosensitive drums 12, 13, 14, 15 onto a transfer belt 60, a second transfer roller 66 which transfers a final form of the image of overlapped unit images of the transfer belt 60 onto a paper sheet ‘P’ as fed, and a fusing part 70 which fixes the final image onto the paper ‘P’ with heat and pressure.
The developing units 52, 53, 54, 55 store developer liquids of different colors, and supply different color developer liquids to the photosensitive drums 12, 13, 14, 15, respectively. The developer liquid contains an ink with toner distributed therein, and a liquid carrier such as Norpar. Norpar is a solvent of hydrocarbon group, which contains mixtures of elements such as C10H22, C11H24, C12H26, C13H28. After the developer liquid is attached onto the respective photosensitive drums 12, 13, 14, 15 to visualize the unit images, the visualized images are overlappingly transferred onto the transfer belt 60. Accordingly, a final image, which is an overlay of overlapped unit images, is transferred onto the paper ‘P’. The developer liquid, especially the ink component of the developer liquid is fixed onto the paper ‘P’ when the paper ‘P’ is passed through the fusing device 70. The liquid carrier of the developer liquid is vaporized by the high temperature heat into a flammable hydrocarbon gas such as methane CH4, and dispersed into the air.
Meanwhile, the flammable hydrocarbon gas is categorized into volatile organic compounds, which gives off an offensive odor and pollutes the area when discharged without proper filtering. In an effort to solve such problems, a variety of suggestions have been made to remove the flammable hydrocarbon gas.
As the currently available removing methods, there is a filtering process which physically removes the gas component by using a carbon filter such as active carbon, a direct combustion process which burns off the gas component in the temperatures of between 600° C. to 800° C., and an oxidation process which oxidizes the gas component into water and carbon dioxide by burning the gas component by use of a catalyst in the relatively low temperatures range of 150° C.-400° C.
The filtering process lacks the ability to decompose the carrier. Accordingly, in the filtering process, a carbon filter would be saturated with the carrier after a certain period of use, and therefore, needs be replaced. Furthermore, the direct combustion process has a safety problem related to high temperature heat.
Considering the problems such as the above, the current wet type electrophotographic image forming apparatus mainly uses an oxidation process for carrier vapor removal, and attention has been focused on the efficiency of oxidizing carrier vapor.